should just need to add this to SlimTray.pl for windows:

push @menu, ["Show SlimServer *Log", "Execute 'http://localhost:9000/log.txt'"];

I like the addition to SlimTray, but think that a button in the web interface 
should be included so that logging is easily viewed on all platforms, as well 
as from other computers.  Most people don't even know about that URL.  It 
should open another browser window instead of trying to display the log in the 
main frameset.  Place the link on the main server settings page and/or on the 
debugging page.

There already is a link in the web interface.  It is in the text above the debug
options

We now have this in the Windows control panel, OSX PrefPane and the web UI.